Arc-welding machine



` Aug. 9 1927.

H. R. WOODROW ARC `WELDING mommay Filed Junele, 1919 es sheets-sheet 1 l ma 'Emana V KIJHHY Aug. 9 1927. 1,638,024

H.R. WooDRoW ARC WELDING MACHINE n Filed June 1,8, 1919 6 sheets-sheet `.2

ug 7 H. R.-wooDRow ARC WELDING MACHINE- e sheets-sheet 3 3 woeMoz #m07 WM Filed Jun'e 18, 1919 mmm,

Aug. 9, 1927. 1,638,024

H. R. WOODROW' ARC WELDING MACHINE Filed June 18, 1919 6 sheets-,Sheet 4 Aug. 9 1927. 1,638,024

H. R. wooDROw ARC WELDING MACHINE Filed June 18, 1919 6 Sheets-Sheet 5 H. R. WOODROW y Aug. 9 1927. l 1,638,024

ARC WELDING MACHINE Filed June 1,8, 1919 6 sheets-sheet 6 l #VQ 40 2A GIU' VYVHVV u Patented dus. 1927.

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Hanni? n. Woonnour, or new roi-in,

N. r., assienon'ro anciens Molinari. on New' ron-n, n. Y. v

.anc-,wurinine Manieren Application filed June l, 1919. Seria-l No. So'.

The invention is an automatic arc welding machine. The object is to provide a compact mechanism, embodying all sequences of operation, which in the existing state of the electric arc weldingl art are per` present time, this operation is mainly limited by the endurance and skill ofthe opera" tor, and under normal conditions can seldom exceed an uninterrupted period of five minutes. The operation of arc welding is deter-- mined by three principal features, namely:

1st. The striking of the arc.

2nd. The uniform and'continuous of the pencil electrode toward the weld.

3rd. The stopping of thearc All of these in their proper order are automatically accomplished by the present machine, as will hereinafter appear.

The inode of organization is as follows: The objects to be welded are placed in. registry and are rotated so that the joint is carried in frontof a fusible electrode. which is here the end of a wire of fusible metal taken from a freely rotating reel. The weldingl larcis struck from the end of the wire, which is continuously fed as consumed to the joint between 4the juxtaposed objects to be welded.

feeding The vwire as it is melted enters the joint,

lill

while at the same time the metal of the objects at the joint isV vrendered plastic by the are, so that said obiects and wire progres-- sively become united until the entiregoint- 1S completed.

In the accompanying drawings p Fig. lis a side elevation of my electric arc welding machine, the electro-magnet and supporting bracket being in vertical section. 1n 'this figureftheend pair C of pivoted roller supporting' arms is omitted in order more clearly to sliowthe reversely threaded shaft 16 and associated parts. Fig. 2 is a front elevation and Fig. 3 is a rear elevation of the machine. Fig. l is an electrical diaJ gram, showing the circuits and parts ofthev machine when not in-operation.l Figs. 5, 6, 7 and 8 are electrical diagrams, showing the circuits established and positions of parts during successive stages of the'operationof the machinee f y Similar letters and numbers of reference indicate like parts- The bed 1 of the .machine is mounted on trucks 2 for convenience in transportation. Upon said bed are standards 3, 3, in which is journaled the transverse pin 1 which carries thefreely rotatable reel 5upon which is wound any desired length of welding wire 6. The reel is preferably made removableV from the standards for purposes of refilling.

The work, as here shown, consists of the .two metal cylinders A., B, which are to be ,esta

dll

arc welded together end to endl Said cyl. Y

inders are supported and rotated as follows:V Hinged in lugs 7 on bed 1 are four pairs C, D, E, F of longitudinally slotted ,arms 8, 9. A. shaft 10 carrying rolls 11 extends 'through the front larms 8,' and a shaft 12, Fign,

carrying" rolls 13 extends through the rear i arms 9 of said pairs. The work--as the cylinders A, B will hereafter for brevitybe termed-rests uponv the rolls 11 and 13.

By moving the front and rear arms of the pairs C, D, E, F nearer together orfurther apart, it is obvious that the work resting on rolls 11 and 13 can be raised or lowered. To move said arms simultaneously for this purpose, l' provide the following mecha-- nism: @n bed 1 are twostandards 1d, 15. Through each standard freely passes a shaftl 16, 17, an on each shaft is a right hand `and aV left hand screw tliread-(see Fig. 1 in which for clearness the end pair@ of arms 8, 9 has been omitted). Respectively on said threads are nuts 18, 19. The front nuts 18 are connected by a rod 20, Fig. 2, and the rear nuts 1% are connected by a rod 21,k Fig.v 3, said rods passing through longitudinal slots respectively `in the front arms 8 and rear arms 9 of pairs D,LE. f

Through the similarly slotted. arms of pair C'extend rods 22, 23 which are connected to the' nuts on screw shaft 16. Fronti the similarly slotted arms of pair F entend rods 24, which' are connected to 'the nuts on shaft 17.- @n the screw shafts 16, 17 are hand wheels 26, by turning which in -one v direction or the other the nuts on said shafts are caused to move toward or away from one another, 'thus drawing together or separat-u ing the members of the pairs of arms C, D., ld, F, and consequently the rolls 11, 12, thus raising or lowering the work A, B; or peru mitting the work support to be adjusted so as to allow work of greater or less diameter to be placed in the machine.

Because the cylindrical work rests upon the rolls 11, 13, said work may be rotated on its axis by positively driving either set of rolls (as here shown, the rear rolls 13 on shaft 12). This is-done by the driving motor of the machine--here an electric motor G, Fig. 1, supported von a bracket on one of the standards 3. The motor shaft and the pinion 31 allows of said rolls 13` being raised or lowered, as before described.

I will now describe the wire feeding mechanism. Extending through-tlie standards S, 3 is a shaft 32, on which is pivoted the arm H. To one end of said arm is connected by a link 33 the plunger core 34, Fig 1, of an electro-magnet l, supported on bracket 85. On the side of said arm near the-opposite end thereof are two feed rolls f 36, 37 which receive between them the wire 6 from reel 5, the.y end of the wire passing through and -protruding 'beyond a 'fixed guide The feedroll 36 is pivoted on a swinging arm 39, which at its end receives a threaded bolt 40 fast on arm H. A wing nut 41 on said bolt moves arm 39 to press feed roll 86V against feed roll 37 in order that said rolls may tightly grasp the wire 6, and when actuated draw said wire from reel 5.I The feeding vof the wire is caused by the 'rotation of feed roll 37, which carries on its shaft a pinion 42 actuated by a worin on shaft 43, which is supported in brackets on y arm H and has at its end a bevel pinion 44 engaging bevel pinion 45, Bevel pinion 45 is on 'ashort shaft passing through bracket 46 on arm 'H and connected by universal joint 47 tothe moving member of expansion joint 48, which in turn is connected by universal joint 49 to a short shaft passing through. bracket 50 on standard 3. Said short shaft at its lower end carries a'spiral gear 51 (dotted lines Fig. 1) which engages a spiral pinion 52 on the shaft of motor G.

Thisk flexible and length variable construction of the connection between bevel pinion and said motor shaft permits :of the swinging of arm H without disturbing the engagement of 'the driving ,gear of feed roll 37. p

The electrical connections: Referring to the diagrainFig. 4, JA (shown in'Fig.-1

supported on'arm H) is a spring switch nor-y i mally open, but closed .when,-bj7 reason .of

electro-magnet I. vswitch communicatingv with the source of the rota-tion of the work in the direction of arrow a, a projection K, which is here a permanent magnet in horseshoe form, adherent to the work and manually applied thereto at a particular moment, as hereinafter explained, contacts with said switch. L is a manually controlled switch on arm H. M is a switch connected by a link to arm H, which closes circuitwhen the right hand end of said arm' is drawn down by N is the main supply current (not shown) by leads d,'f. O, P, and Q, are variable resistances. The motor G is of the differential compound wound type, the shunt field b receiving its supply across the potential fro supply switch N, through the variable resistance O. The series field c is connected in reverse to the shunt field Z), as indicated by the arrows in,

heavy lines: The switch L is manually closed. The circuits established are then as in Fig. 5. The entering supply Ycurrent from main lead d passes through thelower coil e of switch N. venergizingsaid coil. which closes said switch N, and so to closed switch Land to `mainlead f. Switch N being closed. the current dividesy as follows: Part proceeds through ai portion of variable resistance P to electro-magnet I. to feed ioll 37. to wir-e 6 and guide4 38, thence to the brushesof motor G, to series field c, through all of variable resistance (d. and so back to switch N and main lead f. Another part proceeds to a part of variable resistance O, to shunt field Zi, and so back to switch N and main lead f.` These circuits being established and switch N closed, switch L may beo'pened and' so left. The current through series field c and resistance Q is not sufficient to energize electro-magnet l, but is sufficient to start motor G. As soon as the `motor G starts, the wire 6 will gradually be fed forward by the feed rolls 36. 37 until its end makes Contact with the wo-rines shown in Fig. G. At this instant, and for an instant only. a short circuit will vbe formed from the end'of wire 6, through the work (indicated by the dark line on the right hand side of r`the work. in Fig. 6) to roll 13` and so to switch N and lead f. Because of this short circuiting of resistance t2. field 0. and the motor, a comparatively heavy current will at once pass to electromagnet'I, which will draw down the right hand end of arm H, as indicated by the dotted lines in Fig. 6. The period of time .in which this short circuiting and the tilting of arm H takes place is infinitesimal. so that the motor does not stop, but continues rotatinor by inertia. As the arm H ytilts it moves the end of the wire 6 away l cuits being in Figs. 5, 6, 7, 8 indicated byV Leaacae from the Work, and the Welding arcis at once struck between said end and the Work, as indicated at -g in Fig. 7. rlhe first-named feature of the Welding operation, namely, the striking of the Welding arc, is thus accomplished.

The tilting of arm H also closes switch M. The resulting circuits, as shown in Fig". '7, are then as follows: From main lead 0l, to switch N, through a portion of variable resistance P, electro-magnet l, feed roll 37, motor G. series field c, switch M, a portion of variable resistance Q. and so to switch N and main lead f. AS the curr-ent in the shunt field and seri-es field of the motor are now in opposite directions (see 'arrows Fig. 7 the motor will operateat a speed correspending to the povver differential of the fieldsand becomes very sensitive.. That is, the slightest change in the struck arc voltage Will affect its speed, which in turn will govern the spe-ed of both the wire feeding and the Worlr rotating rolls. Previous to the Welding operation, the motor circuit energy consumption. through the variable resistances U, P, Q is exactly adjusted to give the proper amount of current to melt the; weldine wire 6, and onceI set will always maintain the balance for Vay certain size of Work `nd welding Wire. Consequently after the arc has been struck and the feeding and Work rotating mechanism started as described, continuity of the Weld is not impaired by any other factor than-the current supply, length ofl feed Wire vand the length of the welded joint formed between the abutting ends of the cylinders A, B. In

this Way the second feature of the are welding operation, namely, uniform feeding of the Welding IWire and a steady progress of the Weld, is accomplished.

Returning once more to Fig. 7 after the are is struck, and conseouently after the weld has begun. the operator applies to the Work a small horseshoe-shaped permanent magnet so that by its own attraction its polar ends will adhere to said Work. The position of this magnet-is to be such that after the Work has completed its rotation and the weld is finished. the projecting body of the .magnet will meet and close the switch J, as shown in Fig. 8. Circuit is thus closed through the upper coil l2, of supply switch N, whereby said switch is opened andthe Whole machine stopped, the pantsv resuming their initial position shown in Fig. 4. The third main feature. of the welding operation, namely, the stopping of the arc, is thus accomplished. The completed work is then removed. The adjustable resistance P inY the electric -supply circuit allows of a general adjustment of the Welding current in case Wires of different cross sectional areas are used, in which event different amounts of electric energy will be requiredl ln order to protect the eyes of the operator, an eye shield l, 2, of smoked glass or the like may be secured upon the arm H, in front of the arc g.

l claim:

l. An arc welding machine, comprising inean'-I for rotating the work, a fusible electrode, and mechanism for continuously feeding said fusible electrode to the welding joint, the said rotating means comprising two groups of worksupporting rolls. and mea ns for driving one of said groups.

2. An arc welding machine. comprising' a bed, a plurality of pairs of arms. the members of each pair being` hinged to said bed, two shafts respectively carried by corresponding members of said pairs, and work support-ing rolls on said shafts.

3'. An arc Welding machine, as in claim further including means for varying the distance of corresponding members of each pair of arms from their opposite members.

4. An arc Welding machine, as in claim Htl further including a fixed standard on said l bed, a .shaft having right and leftdland screw threads supported in said-standard. nuts on said shaft. respectively engaging said right and left hand threads, and means for connecting said nuts respectively to corresponding members of said pairs of arms.

5. An arc welding machine, comprising an electric motor, a switch in circuittherervith,

mechanism actuated by said motor for movino; the work in the direction of the Welding joint, a fusible electrode, mechanism actuated by said motor for feeding said fusible. electrodel to said joint, means'opcrated by said moving work for opening said switch to break circuit to said motor after a predetermined length of said fusible electrode has been fed to said Work.

6. An arc Welding machine, as in claim 5, the said switch operating means being a permanent magnet manually placed in predetermined position on said Work and magnetically adherentthereto.

7. An arc Welding machine, comprising means for moving the Work in the direction of the Welding joint, an electrode in contact. With said joint, a fusible electrode. means for feeding said fusible electrode, a motor of the differential compound Wound type. actuating said Work-moving and said feedlng means, and circuit connections subst-antially as set forth; whereby changes in the struck arc voltage Will affect the speed of the motor and in turn the speed of said work-` lou support, a switch operated by said support7 a motor, `and circuit connections substantially as set forth; whereby upon the closing of circuit said motor shall be actuated to cause said feeding means to bring said fusible electrode into Contact with the work, then momentarily short-circuited and said electro-magnet energized to actuate said support to carry the fusible electrode away from the Work and so strike the Welding arc, and through said switch to reestablish circuit to raid motor to cause the continued movement of the Work and feeding of the fusible electrode. A i Y 9. The combination of a work support and a Welding electrode holder, said parts being relatively movable to cause an elec trode in said holder to traverse a closed path With reference to said Work support, and means for discontinuing the Welding operation when 'the said path has been traversed by the electrode.

10. In apparatus of the class described the combination of a rotatable Work support, electrodey holding means adapted to maintain an electrode in suitable relation to said Work support and means fordiscontinuing the r0-` tation of the Work support after a predetermined rotative vmovement.

11. In apparatus of the class described the combination of a rotatable Work support, an electrode holder, and means operative after a predetermined movement of the work support to interrupt the current 'to the electrode.

12. In. apparatus of the-class described, the combination of a rotatable Work support an electrode holder, and means operative after a'predetermined movement of the Work support to discontinue the rotation thereof and to interrupt the current to the electrode.

In testimony whereof I have aiiixed my signature. i

HARRY R. WOODROW. 

